This invention relates to a novel, efficient, economic and general-purpose process for isolating monophenolic-bisaryl triazine compounds from polyphenolic-triazines compounds and other impurities. More specifically, this invention relates to a process for isolating the monophenolic-bisaryl triazine compounds by contacting it with a base, an alcohol and/or a hydrocarbon solvent.
Exposure to sunlight and other sources of ultraviolet (UV) radiation is known to cause degradation of a wide variety of materials, especially polymeric materials. For example, polymeric materials such as plastics often discolor and/or become brittle as a result of prolonged exposure to UV light. Accordingly, a large body of art has been developed directed towards materials such as UV light absorbers and stabilizers which are capable of inhibiting such degradation. Other areas of applications for the UV light absorbers include cosmetics (as sunscreen agents), fibers, spandex, inks, photographic materials, and dyes.
A class of materials known to be UV light absorbers are compounds which have aromatic substituents at the 2-, 4-, and 6-positions of the 1,3,5-triazine ring, and in which at least one of the aromatic rings has a hydroxyl substituent at the ortho position to the point of attachment to the triazine ring. In general, this class of compounds is well known in the art. Disclosures of a number of such triazine UV light absorbers (UVA""s) as well as processes for preparing can be found in the following references and references cited therein, all of which are incorporated by reference as fully set forth herein: U.S. Pat. No. 6,239,275; U.S. Pat. No. 6,239,276; U.S. Pat. No. 6,242,597; U.S. Pat. No. 6,225,468 and WO 00/29392.
A preferred class of triazine UVA""s are asymmetrical monophenolic-bisaryl triazines UVA""s based on the 2-(2,4-dihydroxyaryl)-4,6-bisaryl-1,3,5-triazines, e.g., compounds where there are two non-phenolic aromatic groups, and one phenolic aromatic group that is derived from resorcinol, or substituted resorcinol. The 4-hydroxyl group of the parent compound, 2-(2,4-dihydroxyaryl)-4,6-bisaryl-1,3,5-triazine, is generally functionalized to make 2-(2-hydroxy-4-oxyaryl)-4,6-bisaryl-1,3,5-triazine derivatives for end use. 
There are several approaches reported in the literature to make the preferred 2-(2,4-dihydroxyaryl)-4,6-bisaryl-1,3,5-triazine UVA""s. (For a review of the previously known methods for making triazine UVA""s, please see the following articles: 1. H. Brunetti and C. E. Luethi, Helvetica Chimica Acta, vol 55, 1972, pages 1566-1595; 2. S. Tanimoto and M. Yamagata, Senryo to Yakahin, vol. 40(12), 1995, pages 325-339.)
A majority of the approaches consists of three stages. The first stage, which can involve single or multi-steps from the commercial raw materials, deals with the preparation of the key intermediate, 2-chloro-4,6-bisaryl-1,3,5-triazine, which is subsequently arylated in the second stage with 1,3-dihydroxybenzene (resorcinol) or a substituted 1,3-dihydroxybenzene in the presence of Lewis acid to form the parent compound 2-(2,4-dihydroxyaryl)-4,6-bisaryl-1,3,5-triazine. The parent compound 2-(2,4-dihydroxyaryl)-4,6-bisaryl-1,3,5-triazine, as mentioned above, is generally functionalized further, e.g., alkylated, to make the final product 2-(2-hydroxy-4-oxyaryl)-4,6-bisaryl-1,3,5-triazine.

It has been recognized that the most versatile and economical method to prepare asymmetrical monophenolic-bisaryl triazine UVA""s is to use a Friedel-Crafts reaction on cyanuric chloride with non-phenolic aromatics to first form 2-chloro-4,6-bisaryl-1,3,5-triazine, followed by another Friedel-Crafts reaction with the phenolic aromatic, in this case resorcinol, to make the desired monophenolic-bisaryl-triazine. However, it has been realized in the prior art (see, U.S. Pat. No. 3,394,134) that this known process as disclosed in U.S. Pat. No. 3,268,474 gives, only in exceptional cases, rise to the desired disubstituted derivatives of cyanuric chloride with some selectivity. Even when the aromatic compound and cyanuric chloride are reacted in molar proportions (1:1), the result is in general a mixture which contains mono-, di-, and tri-aryl substituted products, and, in addition, unreacted cyanuric chloride (U.S. Pat. No. 3,394,134) (Scheme 1). 
Using the above mentioned process, a useful yield of the desired intermediate 2-chloro-4,6-bisaryl-1,3,5-triazine is obtained only with m-xylene as the aromatic reactant (GB 884802). 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, free of polyresorcinol-triazine impurities, was prepared from the isolated 2-chloro-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine that was purified by recrystallization, before reacting with resorcinol in a second step (see U.S. Pat. No. 3,244,708). The isolation and recrystallization of the 2-chloro-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine results in yield loss. With other aromatics, a difficult to separate mixture of all possible products are formed with no selectivity for the desired 2-chloro-4,6-bisaryl-1,3,5-triazine (For example, see H. Brunetti and C. E. Luethi, Helvetica Chimica Acta, vol 55, 1972, page 1575 and S. Tanimoto and M. Yamagata, Senryo to Yakahin, vol. 40(12),1995, pages 325-339).
When the reaction mixture from the first Friedel-Crafts reaction (Scheme 1) without any purification is treated in a subsequent Friedel-Crafts reaction with resorcinol, the bisaryl-derivative leads to the formation of desired monoresorcinol-bisaryl-triazine, and the monoaryl-substituted product leads to the formation of monoaryl-bisresorcinol derivative. Whereas, the unreacted cyanuric chloride leads to the formation of bis-and tris-resorcinol-triazine derivatives, i.e. polyresorcinol-triazines (see Scheme 2). 
These polyresorcinol-triazine impurities (triazine ring with more than one resorcinol attached) lead to yellowing in the use of the UV absorbers prepared from the monoresorcinol-bisaryl-triazine in various polymer substrates, e.g., in polycarbonates, in lacquers, in automotive top-coatings, etc. Thus it is highly desirable for many such applications that the monoresorcinol-bisaryl-triazine derivative is free of these impurities. Unfortunately, there has been no process known in the literature to isolate monoresorcinol-bisaryl-triazine derivative from the mixture containing polyresorcinol impurities. The lack of selectivity for the bisaryl substitution in the Friedel-Crafts reaction of cyanuric chloride, coupled with the problems associated with the isolation of the bisaryl intermediate and the monoresorcinol-bisaryl-triazine derivative, had severely limited the usefulness of the most versatile and economic approach to the preferred class of triazine UVA""s.
To overcome this obstacle, and to exclude the formation of polyresorcinol-triazines, other economically less attractive routes have been developed in which either cyanuric chloride was not used as starting material, and the triazine ring was synthesized by different methods, or the formation of polyresorcinol impurities was excluded by means of the circuitous routes (For example, see: A. Ostrogovich, Chemiker-Zeitung No. 78, page 738, 1912; von R. Hirt, H. Nidecker and R. Berchtold, Helvitica Chimica Acta, vol. 33, page 1365, 1950; H. Brunetti and C. E. Luethi, Helvetica Chimica Acta, vol 55, 1972, page 1575; U.S. Pat. No. 4,092,466; U.S. Pat. No. 5,084,570; U.S. Pat. No. 5,106,972; U.S. Pat. No. 5,438,138; U.S. Pat. No. 5,726,310; U.S. Pat. No. 6,020,490; EP 0941989 and Japanese Patent 09059263)
An alternate direct approach for the preparation of monoresorcinol-bisaryl-triazine as described in U.S. Pat. No. 6,225,468 B1 from cyanuric chloride also results in the formation of polyresorcinol products, and no method was disclosed to isolate the monoresorcinol-bisaryl-triazine product from the mixture.
More recently, a major breakthrough discovery in the field has led to the development of a process for making the desired bisaryl-monochloro-triazine with exceptionally high selectivity from the Friedel-Crafts reaction of cyanuric halide with aromatics in general (WO 00/29392). However, the selectivity is not 100%, and that still leads to the formation of small amounts of undesired polyresorcinol impurities, in the subsequent reaction with resorcinol in a one-pot process, and tris-aryl-triazine impurity.
As is apparent from the above discussion, it would be a very valuable and highly desirable addition in the field of triazine UV absorbers for a method to isolate monophenolic-bisaryl triazine that is free from the polyphenolic- or polyresorcinol-triazine impurities regardless of the synthesis process.
One of the advantages of the present invention is a highly efficient and very economical method of isolating monophenolic-bisaryl triazine that is substantially free from polyphenolic- or polyresorcinol-triazine impurities, irrespective of the process of its making, without the need for recrystallization. Thus the present invention also eliminates the need for purifying and isolating the intermediate 2-chloro-4,6-bisaryl-1,3,5-triazine from the first Friedel-Crafts reaction of aromatics with cyanuric chloride regardless of its selectivity, and allows to do the second Friedel-Crafts reaction with phenols, such as resorcinol, in a one-pot process to make monophenol-bisaryl-triazines.
Another advantage of the present invention is a method to isolate monophenolic-bisaryl triazine compounds from polyphenolic- or polyresorcinol-triazine, trisaryl-triazine, resorcinol (or substituted resorcinol), phenols, chlorobenzene or dichlorobenzene impurities.
The present invention relates to a process of isolating a compound of Formula 1
where Ar1 and Ar2 are the same or different and are radicals of the compound of Formula 2
and where R1 is hydrogen and R2, R3, R4 and R5, are the same or different and are hydrogen, alkyl of 1 to 24 carbon atoms, haloalkyl of 1 to 24 carbon atoms, aryl of 6 to 24 carbon atoms, alkenyl of 2 to 24 carbon atoms, acyl of 1 to 24 carbon atoms, cycloalkyl of 1 to 24 carbon atoms, cycloacyl of 5 to 24 carbon atoms, aralkyl of 7 to 24 carbon atoms, or aracyl of 6 to 24 carbons atoms, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthalene, OR, NRRxe2x80x2, CONRRxe2x80x2, OCOR, CN, SR, SO2R, and optionally with either of R3 and R4 or R4 and R5 taken together being a part of a saturated or unsaturated fused carbocyclic ring and where each R, Rxe2x80x2, R6, R7, R8, R9, and R10 are the same or different and each is hydrogen, alkyl of 1 to 24 carbon atoms, haloalkyl of 1 to 24 carbon atoms, aryl of 6 to 24 carbon atoms, alkenyl of 2 to 24 carbon atoms, acyl of 1 to 24 carbon atoms, cycloalkyl of 1 to 24 carbon atoms, cycloacyl of 5 to 24 carbon atoms, aralkyl of 7 to 24 carbon atoms, or aracyl of 6 to 24 carbons atoms, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthalene, and optionally with either of R6 and R7, R7 and R8, R8 and R9, or R9 and R10, taken together being a part of a saturated or unsaturated fused carbocyclic ring optionally containing O, N, or S atoms in the ring, and R6, R7, R8, R9, and R10, may be an alkoxy of 1 to 24 carbons, and Y is a direct bond, O, NRxe2x80x3, or SRxe2x80x3 wherein Rxe2x80x3 is hydrogen, alkyl of 1 to 24 carbon atoms, haloalkyl of 1 to 24 carbon atoms, aryl of 6 to 24 carbon atoms, alkenyl of 2 to 24 carbon atoms, acyl of 1 to 24 carbon atoms, cycloalkyl of 1 to 24 carbon atoms, cycloacyl of 5 to 24 carbon atoms, aralkyl of 7 to 24 carbon atoms, or aracyl of 6 to 24 carbons atoms. The process involves the step of contacting a product mixture comprising the compound of Formula 1 with a base, an alcohol, a hydrocarbon solvent or mixtures thereof.
The present involves a process for isolating a monophenolic-bisaryl triazine compound from polyphenolic- or polyresorcinol-triazine impurities. Typically, these impurities result from a synthesis reaction to make the monophenolic-bisaryl triazine compounds from a Friedel-Crafts based reaction as illustrated in General Scheme 1 and General Scheme 2 above. However, it should be noted that the present isolation process can be utilized to isolate monophenolic-bisaryl triazine compounds from polyphenolic- or polyresorcinol-triazine and other impurities in general and should not be limited to any particular synthesis route. In fact, the present process may be generally used to isolate monophenolic-bisaryl triazine compounds from polyphenolic- or polyresorcinol-triazine and other undesired compounds whether or not generated from a synthesis reaction.
The monophenolic-bisaryl triazine compound has the general Formula 1
where Ar1 and Ar2 are the same or different and are radicals of the compound of Formula 2
and where R1 is hydrogen and R2, R3, R4 and R5, are the same or different and are hydrogen, alkyl of 1 to 24 carbon atoms, haloalkyl of 1 to 24 carbon atoms, aryl of 6 to 24 carbon atoms, alkenyl of 2 to 24 carbon atoms, acyl of 1 to 24 carbon atoms, cycloalkyl of 1 to 24 carbon atoms, cycloacyl of 5 to 24 carbon atoms, aralkyl of 7 to 24 carbon atoms, or aracyl of 6 to 24 carbons atoms, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthalene, OR, NRRxe2x80x2, CONRRxe2x80x2, OCOR, CN, SR, SO2R, and optionally with either of R3 and R4 or R4 and R5 taken together being a part of a saturated or unsaturated fused carbocyclic ring and where each R, Rxe2x80x2, R6, R7, R8, R9, and R10 are the same or different and each is hydrogen, alkyl of 1 to 24 carbon atoms, haloalkyl of 1 to 24 carbon atoms, aryl of 6 to 24 carbon atoms, alkenyl of 2 to 24 carbon atoms, acyl of 1 to 24 carbon atoms, cycloalkyl of 1 to 24 carbon atoms, cycloacyl of 5 to 24 carbon atoms, aralkyl of 7 to 24 carbon atoms, or aracyl of 6 to 24 carbons atoms, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthalene, and optionally with either of R6 and R7, R7 and R8, R8 and R9, or R9 and R10, taken together being a part of a saturated or unsaturated fused carbocyclic ring optionally containing O, N, or S atoms in the ring, and R6, R7, R8, R9, and R10, may be an alkoxy of 1 to 24 carbons, and Y is a direct bond, O, NRxe2x80x3, or SRxe2x80x3, wherein Rxe2x80x3 is hydrogen, alkyl of 1 to 24 carbon atoms, haloalkyl of 1 to 24 carbon atoms, aryl of 6 to 24 carbon atoms, alkenyl of 2 to 24 carbon atoms, acyl of 1 to 24 carbon atoms, cycloalkyl of 1 to 24 carbon atoms, cycloacyl of 5 to 24 carbon atoms, aralkyl of 7 to 24 carbon atoms, or aracyl of 6 to 24 carbons atoms.
A preferred compound of Formula 1 is 
where R2, R3 is hydrogen, an alkyl of 1 to 24 carbon atoms or substituted alkyl of 1 to 24 carbon atoms.
A more preferred compound of Formula 1 is: 
In one embodiment of the present invention, a xe2x80x9cproduct mixturexe2x80x9d which comprises the compound of Formula 1 as well as polyphenolic- or polyresorcinol-triazine and other impurities is contacted with a base. These impurities may result from a synthesis process where reactants, undesired by-products, entrained solvents, and the like, are agglomerated together with the desired compound of Formula 1. However, it should be noted that the product mixture does not have to result from a synthesis process and includes any mixture where the desired compound of Formula 1 is combined with undesired polyphenolic- or polyresorcinol-triazine compounds and other impurities.
The product mixture can be in solid or liquid form. For example, in the Friedel-Crafts reaction, the reaction is typically stopped by quenching with water to break the aluminum complex. The compound of Formula 1 and undesired impurities are precipitated out to form the product mixture in a solid form. This precipitated solid form may be directly added to the base, or dissolved with a solvent and added to the base. Any suitable solvent may be used to dissolve the product mixture. Examples of solvents that may be used to dissolve the product mixture include methylisobutylketone, methylethylketone, cyclohexanone, ethyl acetate, butyl acetate, methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, toluene, xylenes and mixtures thereof.
The bases that are suitable to be used in the present invention include inorganic bases, organic bases and mixtures thereof. Inorganic bases include LiOH, NaOH, KOH, Mg(OH)2, Ca(OH)2, Zn(OH)2, Al(OH)3, NH4OH, Li2CO3, Na2CO3, K2CO3, MgCO3, CaCO3, ZnCO3, (NH4)2CO3, BaCO3, CaMg(CO3)2, NaHCO3, KHCO3, (CaO), BaO, LiNH2, NaNH2, KNH2, Mg(NH2)2, Ca(NH2)2, Zn(NH2)2, Al(NH2)3, NaH, CaH2, KH, LiH, and mixtures thereof.
Organic bases include hydrocarbon compounds with C1-C9 cyclic or non-cyclic that contain at least one alkoxide, amine, amide, carboxylate, or thiolate and which may be substituted in one or more positions with a halide, an hydroxyl, an ether, a polyether, a thiol, a thioether, an amine, such as xe2x80x94NHR, xe2x80x94NRxe2x80x22, xe2x80x94NRRxe2x80x2, a carboxylic acid, an ester, or an amide. Preferably, the organic base is an amine that is primary, secondary, tertiary, aliphatic, cyclic, acyclic, aromatic, heteroaromatic, or heterocyclic; or salts of primary amine, secondary amine, alcohol, or acid. Organic bases include CH3Oxe2x88x92, CH3CH2Oxe2x88x92, CH3CH2CH2Oxe2x88x92, (CH3)2CHOxe2x88x92, ((CH3)2CH)2CHOxe2x88x92, CH3CH2CH2CH2Oxe2x88x92, (CH3)3COxe2x88x92, CH3NHxe2x88x92, CH3CH2NHxe2x88x92, CH3CH2CH2NHxe2x88x92, (CH3)2CHNHxe2x88x92, ((CH3)2CH)2CHNHxe2x88x92, CH3CH2CH2CH2NHxe2x88x92, (CH3)3CNHxe2x88x92, (CH3)2Nxe2x88x92, (CH3CH2)2Nxe2x88x92, (CH3CH2CH2)2Nxe2x88x92, ((CH3)2CH)2Nxe2x88x92, (((CH3)2CH)2CH)2Nxe2x88x92, (CH3CH2CH2CH2)2Nxe2x88x92, ((CH3)3C)2Nxe2x88x92, formate, acetate, propylate, butanoate, benzoate; and CH3NH2, CH3CH2NH2, CH3CH2CH2NH2, (CH3)2CHNH2, ((CH3)2CH)2CHNH2, CH3CH2CH2CH2NH2, (CH3)3CNH2, (CH3)2NH, (CH3CH2)2NH, (CH3CH2CH2)2NH, ((CH3)2CH)2NH, ((CH3)2CH)2EtN, (((CH3)2CH)2CH)2NH, (CH3CH2CH2CH2)2NH, ((CH3)3C)2NH, (CH3)3N, (CH3CH2)3N, (CH3CH2CH2)3N, ((CH3)2CH)3N, (((CH3)2CH)2CH)3N, (CH3CH2CH2CH2)3N, ((CH3)3C)3N, pyrrolidine, piperidine, N-alkylpiperidine, piperazine, N-alkylpiperazine, N,N-dialkylpiperazine, morpholine, N-alkylmorpholine, imidazole, pyrrole, pyridine, lutidine, 4-N,N-dimethylaminopyridine, aniline, N,N-dialkylaniline, tetramethylenediamine and mixtures thereof. Organic bases also includes salts of deprotonated carboxylic acids such as salts of formate, acetate, propylate, butanoate, benzoate, with Li, Na, K, Mg, Ca, Al, Zn, or any other suitable cation.
The suitable bases may be dissolved, if desired, in water, an organic solvent, or a mixture of solvents before or after contacting with the product mixture. Examples of suitable solvents include, but are not limited to water, alcohols, acetonitrile, tetrahydrofuran, toluene, heptane and mixtures thereof.
The amount of base to be added to the isolation blend should be enough to adjust the pH of the blend to between about 7.0 to about 14, preferably between about 9 to about 12.
The temperature of the base isolation step may be carried out at temperatures between about 10xc2x0 C. and about the reflux temperature of the isolation blend. Preferably, the temperature is at about 40xc2x0 C. to about the reflux temperature, or about 60xc2x0 to about the reflux temperature.
Preferably, the isolation blend is mixed or stirred by any suitable method such as flow or line mixers, or in agitated vessels using mechanical or gas agitation.
The amount of time needed for the isolation step is between about 10 minutes and about 10 hours, more typically between about 1 to about 4 hours and about 1 to about 2 hours. If heat is used in the isolation step, the isolation blend may be allowed to cool.
If the product mixture is contacted with the base in solid form, the isolation blend after the isolation step is typically filtered to isolate the compound of Formula 1. Although not wishing to be bound by any theory, it is believed that the base solubilizes many of the polyphenolic- or polyresorcinol-triazine compounds and halogen-containing impurities used in the typical Friedel-Crafts reaction such that the solid mass after the isolation step contains mainly the compound of Formula 1 and trisaryl-triazines. The filtrate will be rich in the polyphenolic- or polyresorcinol-triazines and halogen-containing impurities. Impurities in the typically Friedel-Crafts reaction that is believed to be solubilized by the base include, but are not limited to compounds with the following formulas: 
where X, X1, X2 is a halogen or hydroxy and the other substituents are defined above.
Preferred impurities which are solubilized by the base are: 
If a solvent is used to dissolve the product mixture, it is preferred that the solvent used to dissolve the base is substantially immiscible with the solvent used to dissolve the product mixture such that at least two distinct layers are formed. Preferably, the solvent used to dissolve the base is aqueous-based and the solvent used to dissolve the product mixture is organic-based. After the isolation step, it is believed that the aqueous-based layer will contain most of the halogen and polyresorcinol impurities, while the organic-based layer will contain mainly the compound of Formula 1 and trisaryl triazine compounds that are not soluble in the aqueous-based layer. The aqueous-based layer may be removed by any suitable process to leave the organic layer rich in the compound of Formula 1.
Typically, the base isolation step involves treating the reaction mixture such that is xe2x80x9csubstantially freexe2x80x9d of polyphenolic- or polyresorcinol-triazines and halogen-containing impurities. xe2x80x9cSubstantially freexe2x80x9d in the present application means that at least about 80% of the undesired impurities are removed from the reaction mixture during the isolation step. Preferably the amount of impurities removed are at least about 90%, more preferably at least about 95% and even more preferably at least about 98%.
It should be noted that the base isolation step of the present invention may also be used to isolate the polyphenolic- or polyresorcinol-triazine compounds. As mentioned above, the filtrate or the aqueous-based layer is rich in polyphenolic-triazine compounds. If an acid is added to the filtrate or aqueous-based layer, the polyphenolic-triazine compounds precipitate out to a solid form and may be filtered. Any suitable organic or inorganic acid may be used to precipitate the polyphenolic- or polyresorcinol-triazine compounds. Preferably, an inorganic acid is used. Examples of such inorganic acids include, but are not limited to: HCl, HBr, Hl, HNO3, HNO2, H2S, H2SO4, and H3PO4.
Alternatively, after the acidification of the filtrate, the polyphenolic- or polyresorcinol-triazine compounds may be isolated from the aqueous layer by solvent extraction. Any suitable solvent may be used for the solvent extraction. Examples of such suitable solvents include, but are not limited to: ethyl acetate, butyl acetate, dichloromethane and dichloroethane.
In another embodiment of the present invention, the product mixture containing the compound of Formula 1 in solid form is contacted with a hydrocarbon solvent to remove trisaryl-triazine impurities. Suitable hydrocarbon solvents include C1-C20 hydrocarbon compounds, saturated or unsaturated, cyclic or non-cyclic, and aromatic or non-aromatic. Examples of hydrocarbon solvent that may be used include, but are not limited to: benzene, toluene, ethylbenzene, diethylbenzene, xylene, mesitylene, tetralin, hexane, heptane, octane, cyclohexane, and mixtures thereof.
The amount of said hydrocarbon solvent present in the isolation step is about 1 to about 20 parts per part compound of Formula 1, preferably about 3 to about 10 parts hydrocarbon solvent per part compound of Formula 1.
The temperature of the hydrocarbon solvent isolation step is not critical and may be carried out at temperatures between about 10xc2x0 C. to about the reflux temperature of the isolation blend. Preferably, the temperature is about 40xc2x0 C. to about the reflux temperature, or about 60xc2x0 C. to about the reflux temperature of the isolation blend.
The amount of time needed for the isolation step is typically between about 10 minutes to about 10 hours, more typically between about 1 to about 4 hours or about 1 to about 2 hours. If heat is used in the isolation step, the isolation blend is preferably allowed to cool.
Preferably, the isolation blend is mixed or stirred by any suitable method such as flow or line mixers, or in agitated vessels using mechanical or gas agitation.
After the isolation step, the isolation blend is typically filtered to isolate the compound of Formula 1.
Although not wishing to be bound by any theory, it is believed that the hydrocarbon solvent solubilizes the trisaryl triazine compounds from the solid form leaving it richer in the compound of Formula 1 after the isolation step. Typically, the hydrocarbon solvent isolation step involves treating the reaction mixture such that is substantially free of trisaryl-triazine impurities. The filtrate can be concentrated to isolate trisaryl-triazine.
Preferably, the base isolation step and the hydrocarbon isolation step are both used together either in a one-step or in a step-wise fashion, in any order, to isolate the compound of Formula 1. In the present application, the term xe2x80x9cstep-wisexe2x80x9d means a series of isolations steps are conducted. The term xe2x80x9cone-stepxe2x80x9d means when only one isolation step is conducted.
In another embodiment of the present invention, the product mixture containing the compound of Formula 1 is contacted with an alcohol. The product mixture preferably is in solid form. The isolation blend is heated to a temperature of about 40xc2x0 C. to about 200xc2x0 C., preferably about 60xc2x0 C. to about 200xc2x0 C., and more preferably to the reflux temperature of the blend. This isolation step is conducted for a period of about 10 minutes to 10 hours, preferably about 1 to about 4 hours or about 1 to about 2 hours. Preferably, the blend is allowed to cool to below about 40xc2x0 C. If the product mixture is in solid form during this alcohol isolation step, the blend would be typically filtered to isolate the compound of Formula 1.
Any suitable alcohol may be used in this embodiment. Suitable alcohol compounds include carbon compounds of C1-C20, straight chain or branched, saturated or unsaturated, cyclic or non-cyclic, aromatic or non-aromatic, which has at least one hydroxyl group. Examples of suitable alcohol compounds include, but are not limited to: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, 1,2-ethanediol, 3-chloro-1-propanol, 2-hydroxyl-acetic acid, 1-hydroxyl-3-pentanone, cyclohexanol, cyclohexenol, glycerol, benzyl alcohol and mixtures thereof.
The amount of alcohol added in the isolation step is about 1 to about 20 parts per part compound of Formula 1, preferably about 3 to about 10 parts alcohol to per part compound of Formula 1.
Preferably, the isolation blend is mixed or stirred by any suitable method such as flow or line mixers, or in agitated vessels using mechanical or gas agitation.
Although not wishing to be bound by any theory, it is believed that the alcohol solubilizes many of the polyresorcinol and halogen containing impurities used in the typical Friedel-Crafts reaction such that the solid mass after the isolation step contains mainly the compound of Formula 1 and reduced levels of trisaryl-triazines. Typically, the alcohol isolation step involves treating the reaction mixture such that it is substantially free of polyresorcinol and halogen-containing impurities. The alcohol soluble filtrate can be concentrated to recover polyresorcinol-triazines.
It should be noted that it is possible to dissolve the solid product mixture in an organic solvent in this alcohol isolation process. Preferably, the solvent used to dissolve the product mixture is immiscible with the alcohol such that at least two distinct layers are formed. It may be necessary to add some water to the alcohol to form the separate layers. It is believed that the alcohol-based layer will contain most of the halogen and polyresorcinol impurities, and the organic-based layer will contain mainly the compound of Formula 1 and trisaryl triazine compounds that are not soluble in the alcohol-based layer. The alcohol-based layer may be removed by any suitable process to leave the organic layer rich in the compound of Formula 1.
Preferably, the alcohol isolation step and the hydrocarbon isolation step are both used together either in a one-step or in a step-wise fashion, in any order, to isolate the compound of Formula 1.
In another embodiment of the present invention, the product mixture comprising the compound of formula 1 is contacted with at least two components selected from the group consisting of a base, an alcohol and a hydrocarbon solvent. The same processing conditions and amounts as described above may be used in this embodiment. The contacting may be performed in a step-wise or one-step fashion. Preferably, either the base and hydrocarbon solvent components, or the alcohol and hydrocarbon solvent components are processed together.